Generally, thin type display apparatuses having a small occupation area relative to a size of a display screen have been widely distributed. Many of the thin type display apparatuses display an image on a display panel by light from a backlight unit (a light source unit).
There are two types of light source unit, an edge light type which includes a light guide plate facing the display panel and a light source facing a peripheral surface of the light guide plate, and a direct type in which a light source unit such as a light emitting diode (LED) or a cold-cathode fluorescent tube is disposed opposite to the display panel.
In the edge light type, an optical sheet might be directly placed on a front of the light guide plate so as to perform diffusion, polarization of light or the like. In the direct type, the optical sheet might be separated from and disposed opposite to the front of the light source so as to perform diffusion, polarization of light or the like.
As the display apparatus of the edge light type, when the optical sheet is directly placed on the front of the light guide plate, the optical sheet may be wrinkled by heat from the light source, and the quality of the image displayed on the display panel may be decreased.
Therefore, as the display apparatus of the direct type, an edge light type in which a support part for supporting the optical sheet is provided, and an optical sheet that is separated from the light guide plate by the support part could be proposed.
However, when the optical sheet is separated from the light guide plate, the optical sheet moves in a longitudinal direction and a lateral direction during assembly or transportation of the display apparatus, whereby there are problems that the light guide plate may be damaged, and white lines or dots may be visually recognized on the display screen, thus causing a decrease in display quality.
In consideration of the above-described circumstances, it is an object to provide an example embodiment of a light source unit in which a movement of an optical sheet and a decrease of display quality may be prevented even when the optical sheet and a planar light emitting part having a light guide plate, etc., are disposed apart from each other, as well as a display apparatus and a lighting apparatus.
According to one aspect of the example embodiment, there is provided a light source unit, comprising: a light emitting plate that emits light toward a front; an optical sheet that is separated from and faces a front surface of the light emitting plate; a support part that supports an edge portion of the optical sheet; and a holding section that faces an edge portion of a front or a back side of the optical sheet and holds the optical sheet.
In the light source unit according to the example embodiment the support part may face the edge portion of the back side of the optical sheet, and the holding section may be provided between the support part and the edge portion of the back side of the optical sheet.
In the light source unit according to the example embodiment, the holding section may include an adhesive member.
In the light source unit according to the example embodiment, the holding section may include a convex and a concave that are formed on a place of the support part facing the edge portion of the optical sheet.
In the light source unit according to the example embodiment, the optical sheet may be formed in a rectangular shape, one edge part of the optical sheet is to be located at an upper side, and the holding section may be provided on a side of the other edge part of the optical sheet opposite to the one edge part of the optical sheet.
In the light source unit according to the example embodiment, the optical sheet may be formed in a laterally long rectangular shape, and the holding section may be provided on the long edge part of the optical sheet.
According to another aspect of the example embodiment, there is provided a display apparatus comprising: the light source unit according to any one of the above; and a display panel that is disposed on a front side of the light source unit, and displays an image.
In the display apparatus according to the example embodiment, the holding section may be provided between the display panel and an edge portion of the front side of the optical sheet.
According to another aspect of the example embodiment, there is provided a lighting apparatus including: the light source unit according to any one of the above; and a transmissive panel that is disposed on a front side of the optical sheet.
In the lighting apparatus according to the example embodiment, the holding section may be provided between the transmissive panel and an edge portion of the front side of the optical sheet.
In the example embodiment, by providing the holding section on the edge portion of the front or the back side of the optical sheet, for example, the edge portion of the back side of the optical sheet is supported by the support part, or the edge portion of the front side of the optical sheet is supported on the display panel or the transmissive panel which are disposed on the front side of the optical sheet, such that the movement of the optical sheet may be prevented.
In the example embodiment, the holding of the optical sheet may be achieved by using the adhesive member as the holding section, for example, an elastomer member having adhesive or a double-sided tape.
In the example embodiment, the holding of the optical sheet may be achieved by forming a convex and a concave on the support part, and engaging the optical sheet with the convex and concave.
In the example embodiment, one edge part (upper edge part) side of the optical sheet is supported on a back support part, and the other edge part (lower edge part) facing the one edge part is supported by the holding section. When the one edge part side is vertically disposed upward (when the optical sheet is hung), the other edge part side which becomes a free end is held by the holding section, such that the movement of the optical sheet may be effectively prevented.
In the example embodiment, when the optical sheet is disposed without hanging the optical sheet, a long edge part of the optical sheet formed in a laterally long rectangular shape is supported by the holding section. Thereby, even when the optical sheet is expanded or contracted by heat in a longitudinal direction, an occurrence of the wrinkles in the optical sheet may be suppressed.
In the light source unit, the display apparatus and the lighting apparatus according to the example embodiment, by providing the holding section on the edge portion of the front or the back side of the optical sheet, for example, the edge portion of the back side of the optical sheet is supported by the support part, or the edge portion of the front side of the optical sheet is supported on the display or the transmissive panel which are disposed on the front side of the optical sheet, such that the movement of the optical sheet may be prevented.